A voltage dependent anion-selective channel (VDAC) from mitochondrial membranes has been incorporated into planar bilayers. Its channel size, selectivity, voltage dependence and kinetics will be analyzed. It will be purified from mitochondria and its chemical structure determined. Its possible role as the pathway for permeation of small molecules across the outer mitochondrial membrane will be examined. Its possible role in the intracellular control of mitochondrial function will be investigated. Attempts will be made to incorporate other biological channels into planar bilayers in order to study their mechanism of action.